Causes and prevention of postoperative myocardial injury

When a Good Flap Turns Bad: A Temporal Predictive Model for Free Flap Complications

BACKGROUND

 Microsurgical cases are complex plastic surgery procedures with a significant risk of acute postoperative complications. In this study, we use a large-scale database to investigate the temporal progression of complications after microsurgical procedures and the risk imparted by acute postoperative complications on subsequent reconstructive outcomes.

METHODS

 Microsurgery cases were extracted from the National Surgical Quality Improvement Program database by Current Procedural Terminology codes. Postoperative complications were collected for 30 days after surgery and stratified into four temporal periods (postoperative days [PODs] 0-6, 7-13, 14-20, 21-30). Postoperative complication occurrences were incorporated into a weighted multivariate logistic regression model to identify significant predictors of adverse outcomes (p < 0.05). Separately, a regression model was calculated for the time between index operation and reoperation and additional complications.

RESULTS

 The final cohort comprised 19,517 patients, 6,140 (31.5%) of which experienced at least one complication in the first 30 days after surgery. The occurrence of prior complications in the postoperative period was a significant predictor of future adverse outcomes following the initial week after surgery (p < 0.001). Upon predictive analysis, overall model performance was highest in PODs 7 to 13 (71.1% accuracy and the area under a receiver operating characteristic curve 0.684); 2,578 (13.2%) patients underwent at least one reoperation within the first 2 weeks after surgery. The indication for reoperation (p < 0.001) and number of days since surgery (p = 0.0038) were significant predictors of future complications after reoperation.

CONCLUSION

 Prior occurrence of complications in an earlier postoperative week, as well as timing and nature of reoperation, were shown to be significant predictors of future complications.

[Preoperative evaluation of adult patients before elective, non-cardiothoracic surgery : A joint recommendation of the German Society for Anesthesiology and Intensive Care Medicine, the German Society for Surgery and the German Society for Internal Medicine]

The 70 recommendations summarize the current status of preoperative risk evaluation of adult patients prior to elective non-cardiothoracic surgery. Based on the joint publications of the German scientific societies for anesthesiology and intensive care medicine (DGAI), surgery (DGCH), and internal medicine (DGIM), which were first published in 2010 and updated in 2017, as well as the European guideline on preoperative cardiac risk evaluation published in 2022, a comprehensive re-evaluation of the recommendation takes place, taking into account new findings, the current literature, and current guidelines of international professional societies. The revised multidisciplinary recommendation is intended to facilitate a structured and common approach to the preoperative evaluation of patients. The aim is to ensure individualized preparation for the patient prior to surgery and thus to increase patient safety. Taking into account intervention- and patient-specific factors, which are indispensable in the preoperative risk evaluation, the perioperative risk for the patient should be minimized and safety increased. The recommendations for action are summarized under "General Principles (A)," "Advanced Diagnostics (B)," and the "Preoperative Management of Continuous Medication (C)." For the first time, a rating of the individual measures with regard to their clinical relevance has been given in the present recommendation. A joint and transparent agreement is intended to ensure a high level of patient orientation while avoiding unnecessary preliminary examinations, to shorten preoperative examination procedures, and ultimately to save costs. The joint recommendation of DGAI, DGCH and DGIM reflects the current state of knowledge as well as the opinion of experts. The recommendation does not replace the individualized decision between patient and physician about the best preoperative strategy and treatment.

Pathophysiological mechanisms underlying increased circulating cardiac troponin in noncardiac surgery: a narrative review

Assay-specific increases in circulating cardiac troponin are observed in 20-40% of patients after noncardiac surgery, depending on patient age, type of surgery, and comorbidities. Increased cardiac troponin is consistently associated with excess morbidity and mortality after noncardiac surgery. Despite these findings, the underlying mechanisms are unclear. The majority of interventional trials have been designed on the premise that ischaemic cardiac disease drives elevated perioperative cardiac troponin concentrations. We consider data showing that elevated circulating cardiac troponin after surgery could be a nonspecific marker of cardiomyocyte stress. Elevated concentrations of circulating cardiac troponin could reflect coordinated pathological processes underpinning organ injury that are not necessarily caused by ischaemia. Laboratory studies suggest that matching of coronary artery autoregulation and myocardial perfusion-contraction coupling limit the impact of systemic haemodynamic changes in the myocardium, and that type 2 ischaemia might not be the likeliest explanation for cardiac troponin elevation in noncardiac surgery. The perioperative period triggers multiple pathological mechanisms that might cause cardiac troponin to cross the sarcolemma. A two-hit model involving two or more triggers including systemic inflammation, haemodynamic strain, adrenergic stress, and autonomic dysfunction might exacerbate or initiate acute myocardial injury directly in the absence of cell death. Consideration of these diverse mechanisms is pivotal for the design and interpretation of interventional perioperative trials.

Can Orthopaedic Surgeons adequately assess an Electrocardiogram (ECG) trace paper? A cross sectional study

Objectives

The primary objective was to evaluate the ECG trace paper evaluation current knowledge level in a group of Orthopaedic surgeons divided into juniors and seniors according to M.D. degree possession.

Methods

A cross sectional study through self-administered questionnaires at a university hospital Orthopaedic and Trauma Surgery Department. The questionnaire included five sections: 1-Basic participants' characteristics, 2-Participants' perception of their ECG evaluation current knowledge level, 3-The main body of the questionnaire was an ECG quiz (seven); the participant was asked to determine if it was normal and the possible diagnosis, 4-Participants' desired ECG evaluation knowledge level, and 5-Willingness to attend ECG evaluation workshops.

Results

Of the 121 actively working individuals in the department, 96 (97.3 %) finished the questionnaire, and 85 (77.3 %) were valid for final evaluation. The participants' mean age was 30.4 ± 6.92 years, 76.5 % juniors and 23.5 % seniors. 83.5 % of the participants perceived their current ECG evaluation knowledge as none or limited. For participants' ability to evaluate an ECG, higher scores were achieved when determining if the ECG was normal or abnormal, with a mean score percentage of 79.32 % ± 23.27. However, the scores were lower when trying to reach the diagnosis, with a mean score percentage of 43.02 % ± 27.48. There was a significant negative correlation between the participant's age and answering the normality question correctly (r = -0.277, p = 0.01); and a significant positive correlation between answering the diagnosis question correctly and the desired level of knowledge and the intention to attend a workshop about ECG evaluation, r = 0.355 (p = 0.001), and r = 0.223 (p = 0.04), respectively. Only 56.5 % of the participants desired to get more knowledge, and 81.2 % were interested in attending ECG evaluation workshops.

Conclusion

Orthopaedic surgeons showed sufficient knowledge when determining the normality of ECG trace papers; however, they could not reach the proper diagnosis, and Junior surgeons performed slightly better than their senior peers. Most surgeons are willing to attend ECG evaluation and interpretation workshops to improve their knowledge level.

Effects of remote ischaemic preconditioning on myocardial injury after major abdominal surgery in patients at high risk for cardiovascular adverse events in China (RIPC-MAS): protocol for a randomised, sham-controlled, observer-blinded trial

INTRODUCTION

Myocardial injury after non-cardiac surgery (MINS) caused by an ischaemic mechanism is common and is associated with adverse short-term and long-term prognoses. However, MINS is a recent concept, and few studies have prospectively used it as a primary outcome. Remote ischaemic preconditioning (RIPC) is a non-invasive procedure that induces innate cardioprotection and may reduce MINS.

METHODS AND ANALYSIS

This is a multicentre, randomised, sham-controlled, observer-blinded trial. Patients with a high clinical risk of cardiovascular events who are scheduled to undergo major abdominal surgery will be enrolled. A total of 766 participants will be randomised (1:1 ratio) to receive RIPC or control treatment before anaesthesia. RIPC will comprise four cycles of cuff inflation for 5 min to 200 mm Hg and deflation for 5 min. In the controls, an identical-looking cuff will be placed around the arm but will not be actually inflated. The primary outcome will be MINS, defined as at least one postoperative cardiac troponin (cTn) concentration above the 99th percentile upper reference limit of the cTn assay as a result of a presumed ischaemic mechanism. This trial will test the concentration of high-sensitivity cardiac troponin T (hs-cTnT). The secondary outcomes will be hs-cTnT levels reaching/above the prognostically important thresholds, peak hs-cTnT and total hs-cTnT release during the initial 3 days after surgery, length of hospital stay after surgery, length of stay in the intensive care unit, myocardial infarction, major adverse cardiovascular events, cardiac-related death, all-cause death within 30 days, 6 months, 1 year and 2 years after surgery, and postoperative complications and adverse events within 30 days after surgery.

ETHICS AND DISSEMINATION

This study protocol (version 5.0 on 7 April 2023) was approved by the Ethics Committee of Sixth Affiliated Hospital of Sun Yat-sen University. The findings will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05733208.

Inhibition of KMO Ameliorates Myocardial Ischemia Injury via Maintaining Mitochondrial Fusion and Fission Balance

Looking for early diagnostic markers and therapeutic targets is the key to ensuring prompt treatment of myocardial ischemia (MI). Here, a novel biomarker xanthurenic acid (XA) was identified based on metabolomics and exhibited high sensitivity and specificity in the diagnosis of MI patients. Additionally, the elevation of XA was proved to induce myocardial injury in vivo by promoting myocardial apoptosis and ferroptosis. Combining metabolomics and transcriptional data further revealed that kynurenine 3-monooxygenase (KMO) profoundly increased in MI mice, and was closely associated with the elevation of XA. More importantly, pharmacological or heart-specific inhibition of KMO obviously suppressed the elevation of XA and profoundly ameliorated the OGD-induced cardiomyocytes injury and the ligation-induced MI injury. Mechanistically, KMO inhibition effectively restrained myocardial apoptosis and ferroptosis by modulating mitochondrial fission and fusion. In addition, virtual screening and experimental validation were adopted to identify ginsenoside Rb3 as a novel inhibitor of KMO and exhibited great cardioprotective effects by regulating mitochondrial dynamical balance. Taken together, targeting KMO may provide a new approach for the clinical treatment of MI through maintaining mitochondrial fusion and fission balance, and ginsenoside Rb3 showed great potential to be developed as a novel therapeutic drug targeting KMO.

Comparison of Early and Late Surgeries after Coronary Stent Implantation in Patients with Normal Preoperative Troponin Level: A Retrospective Study

Current guidelines recommend delaying noncardiac surgery for 6 months after drug eluting stent implantation. However, this recommendation is largely based on limited evidence and various event definitions. Whether early surgery within 6 months of coronary stent implantation increases myocardial injury in patients with normal preoperative high-sensitivity cardiac troponin I (hs-cTnI) has not yet been investigated. This retrospective study assessed patients who received coronary stent implantation and underwent noncardiac surgery (vascular, abdominal, or thoracic) between 2010 and 2017 with normal preoperative hs-cTnI (n = 186). Patients were divided into early (within 6 months of PCI) and late (after 6 months of PCI) groups. The primary endpoint was the incidence of myocardial injury as diagnosed by hs-cTnI within 3 days post-operation. The secondary outcomes were myocardial infarction, stent thrombosis, emergent coronary revascularization, major bleeding (bleeding requiring transfusion or intracranial bleeding), stroke, renal failure, heart failure, or death within 30 days post-operation. Inverse probability treatment weighting (IPTW) was carried out to adjust for the intergroup baseline differences. Myocardial injury occurred in 28.6% (8/28) and 27.8% (44/158) of the early and late groups, respectively, with no difference between groups (odds ratio [OR] 1.067, 95% confidence interval [CI] 0.404, 2.482; p = 0.886). Secondary outcomes did not differ between the groups. IPTW analysis also showed no differences in myocardial injury and secondary outcomes between the groups. In conclusion, early surgery within 6 months after coronary stent implantation did not increase the incidence of myocardial injury in patients with normal preoperative hs-cTnI.

Trends and Outcomes of Transcatheter Tricuspid Valve Repair and Surgical Tricuspid Valve Repair in Patients With Tricuspid Valve Regurgitation; A Population Based Study

Data on clinical outcomes of transcatheter tricuspid valve repair (TTVR) compared with surgical tricuspid valve repair (STVR) in patients with tricuspid valve regurgitation (TVR) remains limited. Data from the national inpatient sample (2016-2020) and propensity-score matched (PSM) analysis was utilized to determine adjusted odds ratio (aOR) of inpatient mortality and major clinical outcomes of TTVR compated with STVR in patients with TVR. A total of 37,115 patients with TVR were included: 1830 (4.9%) and 35,285 (95.1%) underwent TTVR and STVR, respectively. After PSM, there was no statistically significant difference in baseline characteristics and medical comorbidities between both groups. Compared with STVR, TTVR was associated with lower inpatient mortality (aOR 0.43 [0.31-0.59], P < 0.01), cardiovascular complications (aOR 0.47 [0.3-0.45], P < 0.01), hemodynamic complications (aOR 0.47 [0.4-0.55], P < 0.01), infectious complications (aOR 0.44 [0.34-0.57], P < 0.01), renal complications (aOR 0.56 [0.45-0.64], P < 0.01), and need for blood transfusion. There was no statistically significant difference in odds of major bleeding events (aOR 0.92 [0.64-1.45], P 0.84). Also, TTVR was associated with less mean length of stay (7 days vs 15 days, P < 0.01) and less cost of hospitalization ($59,921 vs $89,618) compared with STVR. There was an increase in the utility of TTVR associated with a decrease in the utility of STVR from 2016 to 2020 (P < 0.01). Our study showed that compared with STVR, TTVR was associated with lower inpatient mortality and clinical events. Nevertheless, further studies are needed to investigate the difference in outcomes between both procedures.

Perioperative strategies to reduce risk of myocardial injury after non-cardiac surgery (MINS): A narrative review

Myocardial injury is a frequent complication of surgical patients after having non-cardiac surgery that is strongly associated with perioperative mortality. While intraoperative anesthesia-related deaths are exceedingly rare, about 1% of patients undergoing non-cardiac surgery die within the first 30 postoperative days. Given the number of surgeries performed annually, death following surgery is the second leading cause of death in the United States. Myocardial injury after non-cardiac surgery (MINS) is defined as an elevation in troponin concentrations within 30 days postoperatively. Although typically asymptomatic, patients with MINS suffer myocardial damage and have a 10% risk of death within 30 days after surgery and excess risks of mortality that persist during the first postoperative year. Many factors for the development of MINS are non-modifiable, such as preexistent coronary artery disease. Preventive measures, systematic approaches to surveillance and treatment standards are still lacking, however many factors are modifiable and should be considered in clinical practice: the importance of hemodynamic control, adequate oxygen supply, metabolic homeostasis, the use of perioperative medications such as statins, anti-thrombotic agents, beta-blockers, or anti-inflammatory agents, as well as some evidence regarding the choice of sedative and analgesic for anesthesia are discussed. Also, as age and complexity in comorbidities of the surgical patient population increase, there is an urgent need to identify patients at risk for MINS and develop prevention and treatment strategies. In this review, we provide an overview of current screening standards and promising preventive options in the perioperative setting and address knowledge gaps requiring further investigation.

Predicting Postoperative Troponin in Patients Undergoing Elective Hip or Knee Arthroplasty: A Comparison of Five Cardiac Risk Prediction Tools

Background

Elderly patients undergoing hip or knee arthroplasty are at a risk for myocardial injury after noncardiac surgery (MINS). We evaluated the ability of five common cardiac risk scores, alone or combined with baseline high-sensitivity cardiac troponin I (hs-cTnI), in predicting MINS and postoperative day 2 (POD2) hs-cTnI levels in patients undergoing elective total hip or knee arthroplasty.

Methods

This study is ancillary to the Genetics-InFormatics Trial (GIFT) of Warfarin Therapy to Prevent Deep Venous Thrombosis, which enrolled patients 65 years and older undergoing elective total hip or knee arthroplasty. The five cardiac risk scores evaluated were the atherosclerotic cardiovascular disease calculator (ASCVD), the Framingham risk score (FRS), the American College of Surgeon's National Surgical Quality Improvement Program (ACS-NSQIP) calculator, the revised cardiac risk index (RCRI), and the reconstructed RCRI (R-RCRI).

Results

None of the scores predicted MINS in women. Among men, the ASCVD (C-statistic of 0.66; p=0.04), ACS-NSQIP (C-statistic of 0.69; p=0.01), and RCRI (C-statistic of 0.64; p=0.04) predicted MINS. Among all patients, spearman correlations (r_s) of the risk scores with the POD2 hs-cTnI levels were 0.24, 0.20, 0.11, 0.11, and 0.08 for the ASCVD, Framingham, ACS-NSQIP, RCRI, and R-RCRI scores, respectively, with p values of <0.001, <0.001, <0.001, 0.006, and 0.025. Baseline hs-cTnI predicted MINS (C-statistics: 0.63 in women and 0.72 in men) and postoperative hs-cTnI (r_s = 0.51, p=0.001).

Conclusion

In elderly patients undergoing elective hip or knee arthroplasty, several of the scores modestly predicted MINS in men and correlated with POD2 hs-cTnI.

Long-Term Outcomes of Perioperative Versus Nonoperative Myocardial Infarction: A Danish Population-Based Cohort Study (2000–2016)

Background:

Perioperative myocardial infarction is a serious cardiovascular complication of noncardiac surgery. The clinical course of perioperative myocardial infarction, other than all-cause mortality, is largely unknown. We examined long-term fatal and nonfatal outcomes of perioperative myocardial infarction compared with nonoperative myocardial infarction.

Methods:

We conducted a population-based cohort study of first-time myocardial infarction in Denmark from 2000 to 2016. We calculated cumulative incidence of all-cause mortality, cardiac mortality, recurrent myocardial infarction, heart failure, stroke, venous thromboembolism, acute kidney injury, and kidney failure with replacement therapy. We computed 5-year risk ratios adjusted for age, sex, year of diagnosis, educational level, and comorbidities.

Results:

We identified 5068 patients with perioperative myocardial infarction and 137 862 patients with nonoperative myocardial infarction. The 5-year risk of all-cause mortality was 67.5% (95% CI, 66.1%–69.0%) for perioperative myocardial infarction patients and 38.0% (95% CI, 37.7%–38.3%) for nonoperative myocardial infarction patients. The adjusted risk ratio of all-cause mortality was 1.13 (95% CI, 1.11–1.16) at 5 years. After adjustment, we found no association between patients with perioperative myocardial infarction and 5-year cardiac mortality, recurrent myocardial infarction, heart failure, stroke, or kidney failure with replacement therapy when compared with nonoperative myocardial infarction patients. Perioperative myocardial infarction patients had a higher relative risk of venous thromboembolism (5-year risk ratio, 1.21 [95% CI, 1.01–1.46]) and acute kidney injury (5-year risk ratio, 1.37 [95% CI, 1.22–1.53]).

Conclusions:

Compared with nonoperative myocardial infarction patients, perioperative myocardial infarction patients had elevated risk of all-cause mortality, venous thromboembolism, and acute kidney failure. In addition to the myocardial infarction component of perioperative myocardial infarction, this poor prognosis seemed associated with the surgery or underlying comorbidities. These findings warrant further research on strategies to reduce the risk of perioperative myocardial infarction and on strategies to manage perioperative myocardial infarction.

Association of Acute Perioperative Myocardial Injury With All-Cause Mortality Within 90 Days After Hip Fracture Repair in the Elderly: A Prospective Study

Introduction

It remains unclear whether acute perioperative myocardial injury (APMI) increases mortality in the elderly. This study aimed to investigate APMI’s association with mortality within 90 days after hip fracture repair in elderly patients.

Materials and Methods

This prospective study enrolled elderly patients admitted to the department of Traumatology and Orthopaedics in XXX Hospital, who underwent surgery in 2018–2019 with a 90-day follow-up. According to survival status within 90 days, survival and death groups were constituted. Clinical, demographic, and laboratory indicators and 90-day mortality post-surgery were recorded. APMI’s association with 90-day mortality post-surgery was analyzed by logistic regression.

Results

Totally 248 participants were enrolled, including 224 and 24 in the survival and death groups, respectively, for a mortality rate of 9.7%. Compared with surviving individuals, the death group was older [81 (75–86) vs 87 (82–89) years], and had higher incidence rates of APMI (24.6% vs 58.3%), intertrochanteric fractures (41.1% vs 62.5%), preoperative atrial fibrillation (8.9% vs 29.2%), and dementia (73.7% vs 95.8%) (all P<.05). They also showed higher pre-injury frail scale scores [1 (0–2) vs 3 (1–4)] and Nottingham hip fracture scores (NHFSs) [4 (4–5) vs 6.5 (5–7)], lower Glomerular filtration [62 (46.1–78.6) vs 44.37 (35–61.92) ml/min], and reduced odds of glomerular filtration rate <60 mL/min (75.0% vs 46.9%) (all P < .05). APMI (OR = 3.294, 95% CI: 1.217–8.913) and NHFS (OR = 2.089, 95% CI: 1.353–3.225) independently predicted 90-day mortality post-surgery (all P<.05).

Conclusions

APMI is associated with increased mortality risk within 90 days after hip fracture repair in elderly patients.

Diagnosis and Management of Patients With Myocardial Injury After Noncardiac Surgery: A Scientific Statement From the American Heart Association

Myocardial injury after noncardiac surgery is defined by elevated postoperative cardiac troponin concentrations that exceed the 99th percentile of the upper reference limit of the assay and are attributable to a presumed ischemic mechanism, with or without concomitant symptoms or signs. Myocardial injury after noncardiac surgery occurs in ≈20% of patients who have major inpatient surgery, and most are asymptomatic. Myocardial injury after noncardiac surgery is independently and strongly associated with both short-term and long-term mortality, even in the absence of clinical symptoms, electrocardiographic changes, or imaging evidence of myocardial ischemia consistent with myocardial infarction. Consequently, surveillance of myocardial injury after noncardiac surgery is warranted in patients at high risk for perioperative cardiovascular complications. This scientific statement provides diagnostic criteria and reviews the epidemiology, pathophysiology, and prognosis of myocardial injury after noncardiac surgery. This scientific statement also presents surveillance strategies and treatment approaches.

Modulation of Peripheral CD4+CD25+Foxp3+ Regulatory T Cells Ameliorates Surgical Stress-Induced Atherosclerotic Plaque Progression in ApoE-Deficient Mice

Systemic inflammation associated with major surgery rapidly accelerates atherosclerotic plaque progression in mice. Regulatory T cells (Tregs) have emerged as important modulators of atherogenesis. In coronary artery disease patients, low frequency of Tregs constitutes an independent risk factor for cardiovascular complications after non-cardiac surgery. In this exploratory analysis, we investigate whether preoperative Treg levels affect surgery-induced atherosclerotic lesion destabilization in a murine model of perioperative stress. After 9 weeks of high-cholesterol diet, atherosclerotic apolipoprotein E-deficient mice with modulated Treg levels were subjected to a 30-minute surgical procedure consisting of general isoflurane anesthesia, laparotomy and moderate blood loss. Controls underwent general anesthesia only. Brachiocephalic arteries were harvested 3 days after the intervention for histomorphological analyses of atherosclerotic plaques. Tregs were depleted by a single dose of anti-CD25 monoclonal antibody (mAb) administered 6 days prior to the intervention. Expansion of Tregs was induced by daily injections of IL-2/anti-IL-2 complex (IL-2C) on three consecutive days starting 3 days before surgery. Isotype-matched antibodies and PBS served as controls. Antibody-mediated modulation was Treg-specific. IL-2C treatment resulted in an eight-fold elevation of peripheral CD4⁺CD25⁺Foxp3⁺ Tregs compared to mice administered with anti-CD25 mAb. In mice treated with PBS and anti-CD25 mAb, surgical stress response caused a significant increase of atherosclerotic plaque necrosis (PBS: p < 0.001; anti-CD25 mAb: p = 0.037). Preoperative Treg expansion abrogated perioperative necrotic core formation (p = 0.556) and significantly enhanced postoperative atherosclerotic plaque stability compared to PBS-treated mice (p = 0.036). Postoperative plaque volume (p = 0.960), stenosis (p = 0.693), lesional collagen (p = 0.258), as well as the relative macrophage (p = 0.625) and smooth muscle cell content (p = 0.178) remained largely unaffected by preoperative Treg levels. In atherosclerotic mice, therapeutic expansion of Tregs prior to major surgery mitigates rapid effects on perioperative stress-driven atherosclerotic plaque destabilization. Future studies will show, whether short-term interventions modulating perioperative inflammation qualify for prevention of cardiovascular events associated with major non-cardiac surgery.

Advances in point-of-care testing for cardiovascular diseases

Point-of-care testing (POCT) is a specific format of diagnostic testing that is conducted without accompanying infrastructure or sophisticated instrumentation. Traditionally, such rapid sample-to-answer assays provide inferior analytical performances to their laboratory counterparts when measuring cardiac biomarkers. Hence, their potentially broad applicability is somewhat bound by their inability to detect clinically relevant concentrations of cardiac troponin (cTn) in the early stages of myocardial injury. However, the continuous refinement of biorecognition elements, the optimization of detection techniques, and the fabrication of tailored fluid handling systems to manage the sensing process has stimulated the production of commercial assays that can support accelerated diagnostic pathways. This review will present the latest commercial POC assays and examine their impact on clinical decision-making. The individual elements that constitute POC assays will be explored, with an emphasis on aspects that contribute to economically feasible and highly sensitive assays. Furthermore, the prospect of POCT imparting a greater influence on early interventions for medium to high-risk individuals and the potential to re-shape the paradigm of cardiovascular risk assessments will be discussed.

Association between postsurgical pain and heart rate variability: protocol for a scoping review

INTRODUCTION

Surgical interventions can elicit neuroendocrine responses and sympathovagal imbalance, ultimately affecting cardiac autonomic function. Cardiac complications account for 30% of postoperative complications and are the leading cause of morbidity and mortality following non-cardiac surgery. One cardiovascular parameter, heart rate variability (HRV), has been found to be predictive of postoperative morbidity and mortality. HRV is defined as variation in time intervals between heartbeats and is affected by cardiac autonomic balance. Furthermore, altered HRV has been shown to predict cardiovascular events in non-surgical settings. In multiple studies, experimentally induced pain in healthy humans leads to reduced HRV suggesting a causal relationship. In a different studies, chronic pain has been associated with altered HRV, however, in the setting of clinical pain conditions, it remains unclear how much HRV impairment is due to pain itself versus autonomic changes related to analgesia. We aim to review the available evidence describing the association between postsurgical pain and HRV alterations in the early postoperative period.

METHODS AND ANALYSIS

We will conduct a scoping review of relevant studies using detailed searches of MEDLINE and EMBASE, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Included studies will involve participants undergoing non-cardiac surgery and investigate outcomes of (1) measures of pain intensity; (2) measures of HRV and (3) statistical assessment of association between #1 and #2. As secondary review outcomes included studies will also be examined for other cardiovascular events and for their attempts to control for analgesic treatment and presurgical HRV differences among treatment groups in the analysis. This work aims to synthesise available evidence to inform future research questions related to postsurgical pain and cardiac complications.

ETHICS AND DISSEMINATION

Ethics review and approval is not required for this review. The results will be submitted for publication in peer-reviewed journals.

Pretransplant left ventricular hypertrophy in association with postoperative myocardial injury in liver transplantation

Pretransplant left ventricular hypertrophy (LVH) is a common finding during preoperative cardiac evaluation. We hypothesized that patients with pretransplant LVH were associated with a higher risk of postoperative myocardial injury (PMI) in adult patients undergoing liver transplantation (LT). A retrospective cohort analysis was performed by reviewing the medical records of adult patients who underwent LT between January 2006 and October 2013. Of 893 patients, the incidences of mild, moderate, and severe LVH were 7.8%, 5.6%, and 2.5%, respectively. Propensity match was used to eliminate the pretransplant imbalance between the LVH and non-LVH groups. In after-match patients, 23.5% of LVH patients developed PMI compared to 11.8% in the control group (P = .011). The incidence of PMI in patients with moderate-severe degrees of LVH was significantly higher compared with that in patients with mild LVH (27.9% vs 19.1%, P = .016). When controlling intraoperative variables, patients with LVH had 4.5 higher odds of developing PMI (95% CI1.18-17.19, P = .028). Patients experiencing PMI had significantly higher 1-year mortality (37.5% vs 15.7%, log-rank test P < .001). Our results suggest that patients with pretransplant LVH were at a high risk of developing PMI and should be monitored closely in the perioperative period. More studies are warranted.

Sequential Surgical Procedures in Vascular Surgery Patients Are Associated With Perioperative Adverse Cardiac Events

Patients at elevated cardiovascular risk are prone to perioperative cardiovascular complications, like myocardial injury after non-cardiac surgery (MINS). We have demonstrated in a mouse model of atherosclerosis that perioperative stress leads to an increase in plaque volume and higher plaque vulnerability. Regulatory T cells (Tregs) play a pivotal role in development and destabilization of atherosclerotic plaques. For this exploratory post-hoc analysis we identified 40 patients recruited into a prospective perioperative biomarker study, who within the inclusion period underwent sequential open vascular surgery. On the basis of protein markers measured in the biomarker study, we evaluated the perioperative inflammatory response in patients' plasma before and after index surgery as well as before and after a second surgical procedure. We also analyzed available immunohistochemistry samples to describe plaque vulnerability in patients who underwent bilateral carotid endarterectomy (CEA) in two subsequent surgical procedures. Finally, we assessed if MINS was associated with sequential surgery. The inflammatory response of both surgeries was characterized by postoperative increases of interleukin-6,−10, Pentraxin 3 and C-reactive protein with no clear-cut difference between the two time points of surgery. Plaques from CEA extracted during the second surgery contained less Tregs, as measured by Foxp3 staining, than plaques from the first intervention. The 2nd surgical procedure was associated with MINS. In conclusion, we provide descriptive evidence that sequential surgical procedures involve repeat inflammation, and we hypothesize that elevated rates of cardiovascular complications after the second procedure could be related to reduced levels of intraplaque Tregs, a finding that deserves confirmatory testing and mechanistic exploration in future populations.

Association between intraoperative hypotension and postoperative myocardial injury in patients with prior coronary stents undergoing high-risk surgery: a retrospective study

PURPOSE

We conducted a single-center retrospective study to evaluate the effects of intraoperative hypotension (IOH) on postoperative myocardial injury during major noncardiac surgery in patients with prior coronary stents with preoperatively normal cardiac troponin I levels. Although IOH is assumed to increase the risk of postoperative myocardial injury in patients with prior coronary stents, the level and duration of hazardous low blood pressure have not been clarified.

METHODS

Of 2517 patients with prior coronary stents undergoing noncardiac surgery between January 2010 and March 2017, we analyzed 195 undergoing major surgery (vascular, abdominal, and thoracic surgery) who had a normal preoperative high-sensitivity cardiac troponin I (hs-cTnI) level and were followed up postoperatively within 3 days. Postoperative myocardial injury was defined as a hs-cTnI level greater than the 99th percentile reference value. Primary IOH exposure was defined as a decrease of ≥ 50%, 40%, or 30% from the preinduction mean blood pressure. Additional definition of IOH was absolute mean blood pressure < 70, < 60 or < 50 mmHg. Multivariate logistic regression was used to model the exposure and myocardial injury.

RESULTS

Myocardial injury occurred in 53 (27.2%) cases. The predefined levels of IOH were not significantly associated with postoperative myocardial injury, but intraoperative continuous inotropes/vasopressors use was significantly higher in patients with myocardial injury (P = 0.004). Operation time ≥ 166 min (OR = 2.823, 95% CI 1.184-6.731, P = 0.019) and abdominal vascular surgery (OR = 2.693, 95% CI 1.213-5.976, P = 0.015) were independent risk factors for myocardial injury.

CONCLUSION

Although patients with prior coronary stents with normal hs-cTnI levels did not show association between varying levels of IOH and postoperative myocardial injury after noncardiac surgery, intraoperative need of continuous inotropes/vasopressors was higher in patients with postoperative myocardial injury. Abdominal vascular surgery and surgical time were independent risk factors for myocardial injury after surgery.